Q. A 53 year-old female presents to clinic for bilateral feet pain. She characterizes the pain as a stabbing sensation located that the bottom of her feet. She is unable to stand on her feet for long periods of time due to the pain. She has a medical history of vitamin B12 deficiency. On neurological exam, she has reduced sensation to pinprick and temperature. Proprioception and vibration are intact. She has 5/5 strength in her upper and lower extremities throughout. Her reflexes are reduced in all her extremities. Her clinical presentation is concerning for a peripheral neuropathy. Where within the spinal cord do the first order neurons responsible for the patient’s symptoms cross?